mtd: nand: Sync with Linux v4.6

Updates the NAND code to match Linux v4.6.  The previous sync was from
Linux v4.1 in commit d3963721d93fafa.

Note that none of the individual NAND drivers tracked Linux closely
enough to be synced themselves, other than manually applying a few
cross-tree changes.

Signed-off-by: Scott Wood <oss@buserror.net>
Tested-by: Heiko Schocher <hs@denx.de>
diff --git a/drivers/mtd/nand/atmel_nand.c b/drivers/mtd/nand/atmel_nand.c
index a81b96d..75e8307 100644
--- a/drivers/mtd/nand/atmel_nand.c
+++ b/drivers/mtd/nand/atmel_nand.c
@@ -513,7 +513,7 @@
 			if (err_nbr == -1) {
 				dev_err(host->dev, "PMECC: Too many errors\n");
 				mtd->ecc_stats.failed++;
-				return -EIO;
+				return -EBADMSG;
 			} else {
 				pmecc_correct_data(mtd, buf_pos, ecc, i,
 					host->pmecc_bytes_per_sector, err_nbr);
@@ -562,7 +562,7 @@
 	stat = pmecc_readl(host->pmecc, isr);
 	if (stat != 0)
 		if (pmecc_correction(mtd, stat, buf, &oob[eccpos[0]]) != 0)
-			return -EIO;
+			return -EBADMSG;
 
 	return 0;
 }
@@ -1112,7 +1112,7 @@
 		 * We can't correct so many errors */
 		dev_warn(host->dev, "atmel_nand : multiple errors detected."
 				" Unable to correct.\n");
-		return -EIO;
+		return -EBADMSG;
 	}
 
 	/* if there's a single bit error : we can correct it */
diff --git a/drivers/mtd/nand/davinci_nand.c b/drivers/mtd/nand/davinci_nand.c
index be9d666..48a8ca7 100644
--- a/drivers/mtd/nand/davinci_nand.c
+++ b/drivers/mtd/nand/davinci_nand.c
@@ -243,7 +243,7 @@
 					 "%d\n", find_byte, find_bit);
 				return 1;
 			} else {
-				return -1;
+				return -EBADMSG;
 			}
 		} else if (!(diff & (diff - 1))) {
 			/* Single bit ECC error in the ECC itself,
@@ -254,7 +254,7 @@
 		} else {
 			/* Uncorrectable error */
 			MTDDEBUG(MTD_DEBUG_LEVEL0, "ECC UNCORRECTED_ERROR 1\n");
-			return -1;
+			return -EBADMSG;
 		}
 	}
 	return 0;
@@ -701,7 +701,7 @@
 		return 0;
 	} else if (iserror == ECC_STATE_TOO_MANY_ERRS) {
 		val = __raw_readl(&davinci_emif_regs->nanderrval1);
-		return -1;
+		return -EBADMSG;
 	}
 
 	numerrors = ((__raw_readl(&davinci_emif_regs->nandfsr) >> 16)
diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c
index 3ae7545..601e744 100644
--- a/drivers/mtd/nand/denali.c
+++ b/drivers/mtd/nand/denali.c
@@ -48,8 +48,10 @@
  * this macro allows us to convert from an MTD structure to our own
  * device context (denali) structure.
  */
-#define mtd_to_denali(m) \
-	container_of(mtd_to_nand(m), struct denali_nand_info, nand)
+static inline struct denali_nand_info *mtd_to_denali(struct mtd_info *mtd)
+{
+	return container_of(mtd_to_nand(mtd), struct denali_nand_info, nand);
+}
 
 /*
  * These constants are defined by the driver to enable common driver
@@ -866,8 +868,7 @@
  * by write_page above.
  */
 static int denali_write_page(struct mtd_info *mtd, struct nand_chip *chip,
-				const uint8_t *buf, int oob_required,
-				int page)
+				const uint8_t *buf, int oob_required, int page)
 {
 	struct denali_nand_info *denali = mtd_to_denali(mtd);
 
@@ -891,8 +892,8 @@
  * write_page() function above.
  */
 static int denali_write_page_raw(struct mtd_info *mtd, struct nand_chip *chip,
-					const uint8_t *buf, int oob_required,
-					int page)
+				 const uint8_t *buf, int oob_required,
+				 int page)
 {
 	struct denali_nand_info *denali = mtd_to_denali(mtd);
 
@@ -991,7 +992,7 @@
 			debug("  ECC error cause by erased block\n");
 			/* false alarm, return the 0xFF */
 		} else {
-			return -EIO;
+			return -EBADMSG;
 		}
 	}
 	memcpy(buf, denali->buf.dma_buf, mtd->writesize);
@@ -1176,12 +1177,13 @@
 
 static int denali_init(struct denali_nand_info *denali)
 {
+	struct mtd_info *mtd = nand_to_mtd(&denali->nand);
 	int ret;
 
 	denali_hw_init(denali);
 
-	denali->mtd->name = "denali-nand";
-	denali->mtd->owner = THIS_MODULE;
+	mtd->name = "denali-nand";
+	mtd->owner = THIS_MODULE;
 
 	/* register the driver with the NAND core subsystem */
 	denali->nand.select_chip = denali_select_chip;
@@ -1195,7 +1197,7 @@
 	 * this is the first stage in a two step process to register
 	 * with the nand subsystem
 	 */
-	if (nand_scan_ident(denali->mtd, denali->max_banks, NULL)) {
+	if (nand_scan_ident(mtd, denali->max_banks, NULL)) {
 		ret = -ENXIO;
 		goto fail;
 	}
@@ -1241,13 +1243,13 @@
 	nand_oob.eccbytes = denali->nand.ecc.bytes;
 	denali->nand.ecc.layout = &nand_oob;
 
-	writel(denali->mtd->erasesize / denali->mtd->writesize,
+	writel(mtd->erasesize / mtd->writesize,
 	       denali->flash_reg + PAGES_PER_BLOCK);
 	writel(denali->nand.options & NAND_BUSWIDTH_16 ? 1 : 0,
 	       denali->flash_reg + DEVICE_WIDTH);
-	writel(denali->mtd->writesize,
+	writel(mtd->writesize,
 	       denali->flash_reg + DEVICE_MAIN_AREA_SIZE);
-	writel(denali->mtd->oobsize,
+	writel(mtd->oobsize,
 	       denali->flash_reg + DEVICE_SPARE_AREA_SIZE);
 	if (readl(denali->flash_reg + DEVICES_CONNECTED) == 0)
 		writel(1, denali->flash_reg + DEVICES_CONNECTED);
@@ -1260,12 +1262,12 @@
 	denali->nand.ecc.read_oob = denali_read_oob;
 	denali->nand.ecc.write_oob = denali_write_oob;
 
-	if (nand_scan_tail(denali->mtd)) {
+	if (nand_scan_tail(mtd)) {
 		ret = -ENXIO;
 		goto fail;
 	}
 
-	ret = nand_register(0, denali->mtd);
+	ret = nand_register(0, mtd);
 
 fail:
 	return ret;
@@ -1280,13 +1282,6 @@
 		return -ENOMEM;
 
 	/*
-	 * If CONFIG_SYS_NAND_SELF_INIT is defined, each driver is responsible
-	 * for instantiating struct nand_chip, while drivers/mtd/nand/nand.c
-	 * still provides a "struct mtd_info nand_info" instance.
-	 */
-	denali->mtd = &denali->nand.mtd;
-
-	/*
 	 * In the future, these base addresses should be taken from
 	 * Device Tree or platform data.
 	 */
diff --git a/drivers/mtd/nand/denali.h b/drivers/mtd/nand/denali.h
index db1457a..0e098bd 100644
--- a/drivers/mtd/nand/denali.h
+++ b/drivers/mtd/nand/denali.h
@@ -436,7 +436,6 @@
 #define DT		3
 
 struct denali_nand_info {
-	struct mtd_info *mtd;
 	struct nand_chip nand;
 	int flash_bank; /* currently selected chip */
 	int status;
diff --git a/drivers/mtd/nand/denali_spl.c b/drivers/mtd/nand/denali_spl.c
index 1587413..c693032 100644
--- a/drivers/mtd/nand/denali_spl.c
+++ b/drivers/mtd/nand/denali_spl.c
@@ -41,7 +41,7 @@
 
 		if (intr_status & INTR_STATUS__ECC_UNCOR_ERR) {
 			debug("Uncorrected ECC detected\n");
-			return -EIO;
+			return -EBADMSG;
 		}
 
 		if (intr_status & irq_mask)
diff --git a/drivers/mtd/nand/mpc5121_nfc.c b/drivers/mtd/nand/mpc5121_nfc.c
index 362d393..8a8775c 100644
--- a/drivers/mtd/nand/mpc5121_nfc.c
+++ b/drivers/mtd/nand/mpc5121_nfc.c
@@ -100,7 +100,6 @@
 #define NFC_WPC_UNLOCK		(1 << 2)
 
 struct mpc5121_nfc_prv {
-	struct mtd_info mtd;
 	struct nand_chip chip;
 	int irq;
 	void __iomem *regs;
diff --git a/drivers/mtd/nand/mxc_nand.c b/drivers/mtd/nand/mxc_nand.c
index d4e14b5..7221d0b 100644
--- a/drivers/mtd/nand/mxc_nand.c
+++ b/drivers/mtd/nand/mxc_nand.c
@@ -19,7 +19,6 @@
 #define DRIVER_NAME "mxc_nand"
 
 struct mxc_nand_host {
-	struct mtd_info			mtd;
 	struct nand_chip		*nand;
 
 	struct mxc_nand_regs __iomem	*regs;
@@ -681,7 +680,7 @@
 				       mtd->writesize / nand_chip->subpagesize
 					    - subpages);
 			}
-			return -1;
+			return -EBADMSG;
 		}
 		ecc_status >>= 4;
 		subpages--;
@@ -713,7 +712,7 @@
 	if (((ecc_status & 0x3) == 2) || ((ecc_status >> 2) == 2)) {
 		MTDDEBUG(MTD_DEBUG_LEVEL0,
 		      "MXC_NAND: HWECC uncorrectable 2-bit ECC error\n");
-		return -1;
+		return -EBADMSG;
 	}
 
 	return 0;
diff --git a/drivers/mtd/nand/mxc_nand_spl.c b/drivers/mtd/nand/mxc_nand_spl.c
index 6ac2c96..841fb5b 100644
--- a/drivers/mtd/nand/mxc_nand_spl.c
+++ b/drivers/mtd/nand/mxc_nand_spl.c
@@ -232,7 +232,7 @@
 	nfc_nand_read_page(page_address);
 
 	if (nfc_nand_check_ecc())
-		return -1;
+		return -EBADMSG;
 
 	src = (u32 *)&nfc->main_area[0][0];
 	dst = (u32 *)buf;
diff --git a/drivers/mtd/nand/mxs_nand.c b/drivers/mtd/nand/mxs_nand.c
index 5291330..7be1f86 100644
--- a/drivers/mtd/nand/mxs_nand.c
+++ b/drivers/mtd/nand/mxs_nand.c
@@ -961,7 +961,7 @@
  * Thus, this function is only called when we want *all* blocks to look good,
  * so it *always* return success.
  */
-static int mxs_nand_block_bad(struct mtd_info *mtd, loff_t ofs, int getchip)
+static int mxs_nand_block_bad(struct mtd_info *mtd, loff_t ofs)
 {
 	return 0;
 }
diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 62e70a7..74c563c 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -1,6 +1,4 @@
 /*
- *  drivers/mtd/nand.c
- *
  *  Overview:
  *   This is the generic MTD driver for NAND flash devices. It should be
  *   capable of working with almost all NAND chips currently available.
@@ -45,8 +43,6 @@
 #include <asm/io.h>
 #include <asm/errno.h>
 
-static bool is_module_text_address(unsigned long addr) {return 0;}
-
 /* Define default oob placement schemes for large and small page devices */
 static struct nand_ecclayout nand_oob_8 = {
 	.eccbytes = 3,
@@ -343,13 +339,12 @@
  * nand_block_bad - [DEFAULT] Read bad block marker from the chip
  * @mtd: MTD device structure
  * @ofs: offset from device start
- * @getchip: 0, if the chip is already selected
  *
  * Check, if the block is bad.
  */
-static int nand_block_bad(struct mtd_info *mtd, loff_t ofs, int getchip)
+static int nand_block_bad(struct mtd_info *mtd, loff_t ofs)
 {
-	int page, chipnr, res = 0, i = 0;
+	int page, res = 0, i = 0;
 	struct nand_chip *chip = mtd_to_nand(mtd);
 	u16 bad;
 
@@ -358,15 +353,6 @@
 
 	page = (int)(ofs >> chip->page_shift) & chip->pagemask;
 
-	if (getchip) {
-		chipnr = (int)(ofs >> chip->chip_shift);
-
-		nand_get_device(mtd, FL_READING);
-
-		/* Select the NAND device */
-		chip->select_chip(mtd, chipnr);
-	}
-
 	do {
 		if (chip->options & NAND_BUSWIDTH_16) {
 			chip->cmdfunc(mtd, NAND_CMD_READOOB,
@@ -391,11 +377,6 @@
 		i++;
 	} while (!res && i < 2 && (chip->bbt_options & NAND_BBT_SCAN2NDPAGE));
 
-	if (getchip) {
-		chip->select_chip(mtd, -1);
-		nand_release_device(mtd);
-	}
-
 	return res;
 }
 
@@ -533,14 +514,12 @@
  * nand_block_checkbad - [GENERIC] Check if a block is marked bad
  * @mtd: MTD device structure
  * @ofs: offset from device start
- * @getchip: 0, if the chip is already selected
  * @allowbbt: 1, if its allowed to access the bbt area
  *
  * Check, if the block is bad. Either by reading the bad block table or
  * calling of the scan function.
  */
-static int nand_block_checkbad(struct mtd_info *mtd, loff_t ofs, int getchip,
-			       int allowbbt)
+static int nand_block_checkbad(struct mtd_info *mtd, loff_t ofs, int allowbbt)
 {
 	struct nand_chip *chip = mtd_to_nand(mtd);
 
@@ -551,17 +530,22 @@
 	}
 
 	if (!chip->bbt)
-		return chip->block_bad(mtd, ofs, getchip);
+		return chip->block_bad(mtd, ofs);
 
 	/* Return info from the table */
 	return nand_isbad_bbt(mtd, ofs, allowbbt);
 }
 
-/* Wait for the ready pin, after a command. The timeout is caught later. */
+/**
+ * nand_wait_ready - [GENERIC] Wait for the ready pin after commands.
+ * @mtd: MTD device structure
+ *
+ * Wait for the ready pin after a command, and warn if a timeout occurs.
+ */
 void nand_wait_ready(struct mtd_info *mtd)
 {
 	struct nand_chip *chip = mtd_to_nand(mtd);
-	u32 timeo = (CONFIG_SYS_HZ * 20) / 1000;
+	u32 timeo = (CONFIG_SYS_HZ * 400) / 1000;
 	u32 time_start;
 
 	time_start = get_timer(0);
@@ -571,6 +555,9 @@
 			if (chip->dev_ready(mtd))
 				break;
 	}
+
+	if (!chip->dev_ready(mtd))
+		pr_warn("timeout while waiting for chip to become ready\n");
 }
 EXPORT_SYMBOL_GPL(nand_wait_ready);
 
@@ -871,15 +858,13 @@
  * @mtd: MTD device structure
  * @chip: NAND chip structure
  *
- * Wait for command done. This applies to erase and program only. Erase can
- * take up to 400ms and program up to 20ms according to general NAND and
- * SmartMedia specs.
+ * Wait for command done. This applies to erase and program only.
  */
 static int nand_wait(struct mtd_info *mtd, struct nand_chip *chip)
 {
 
-	int status, state = chip->state;
-	unsigned long timeo = (state == FL_ERASING ? 400 : 20);
+	int status;
+	unsigned long timeo = 400;
 
 	led_trigger_event(nand_led_trigger, LED_FULL);
 
@@ -912,6 +897,135 @@
 	return status;
 }
 
+#define BITS_PER_BYTE 8
+
+/**
+ * nand_check_erased_buf - check if a buffer contains (almost) only 0xff data
+ * @buf: buffer to test
+ * @len: buffer length
+ * @bitflips_threshold: maximum number of bitflips
+ *
+ * Check if a buffer contains only 0xff, which means the underlying region
+ * has been erased and is ready to be programmed.
+ * The bitflips_threshold specify the maximum number of bitflips before
+ * considering the region is not erased.
+ * Note: The logic of this function has been extracted from the memweight
+ * implementation, except that nand_check_erased_buf function exit before
+ * testing the whole buffer if the number of bitflips exceed the
+ * bitflips_threshold value.
+ *
+ * Returns a positive number of bitflips less than or equal to
+ * bitflips_threshold, or -ERROR_CODE for bitflips in excess of the
+ * threshold.
+ */
+static int nand_check_erased_buf(void *buf, int len, int bitflips_threshold)
+{
+	const unsigned char *bitmap = buf;
+	int bitflips = 0;
+	int weight;
+
+	for (; len && ((uintptr_t)bitmap) % sizeof(long);
+	     len--, bitmap++) {
+		weight = hweight8(*bitmap);
+		bitflips += BITS_PER_BYTE - weight;
+		if (unlikely(bitflips > bitflips_threshold))
+			return -EBADMSG;
+	}
+
+	for (; len >= 4; len -= 4, bitmap += 4) {
+		weight = hweight32(*((u32 *)bitmap));
+		bitflips += 32 - weight;
+		if (unlikely(bitflips > bitflips_threshold))
+			return -EBADMSG;
+	}
+
+	for (; len > 0; len--, bitmap++) {
+		weight = hweight8(*bitmap);
+		bitflips += BITS_PER_BYTE - weight;
+		if (unlikely(bitflips > bitflips_threshold))
+			return -EBADMSG;
+	}
+
+	return bitflips;
+}
+
+/**
+ * nand_check_erased_ecc_chunk - check if an ECC chunk contains (almost) only
+ *				 0xff data
+ * @data: data buffer to test
+ * @datalen: data length
+ * @ecc: ECC buffer
+ * @ecclen: ECC length
+ * @extraoob: extra OOB buffer
+ * @extraooblen: extra OOB length
+ * @bitflips_threshold: maximum number of bitflips
+ *
+ * Check if a data buffer and its associated ECC and OOB data contains only
+ * 0xff pattern, which means the underlying region has been erased and is
+ * ready to be programmed.
+ * The bitflips_threshold specify the maximum number of bitflips before
+ * considering the region as not erased.
+ *
+ * Note:
+ * 1/ ECC algorithms are working on pre-defined block sizes which are usually
+ *    different from the NAND page size. When fixing bitflips, ECC engines will
+ *    report the number of errors per chunk, and the NAND core infrastructure
+ *    expect you to return the maximum number of bitflips for the whole page.
+ *    This is why you should always use this function on a single chunk and
+ *    not on the whole page. After checking each chunk you should update your
+ *    max_bitflips value accordingly.
+ * 2/ When checking for bitflips in erased pages you should not only check
+ *    the payload data but also their associated ECC data, because a user might
+ *    have programmed almost all bits to 1 but a few. In this case, we
+ *    shouldn't consider the chunk as erased, and checking ECC bytes prevent
+ *    this case.
+ * 3/ The extraoob argument is optional, and should be used if some of your OOB
+ *    data are protected by the ECC engine.
+ *    It could also be used if you support subpages and want to attach some
+ *    extra OOB data to an ECC chunk.
+ *
+ * Returns a positive number of bitflips less than or equal to
+ * bitflips_threshold, or -ERROR_CODE for bitflips in excess of the
+ * threshold. In case of success, the passed buffers are filled with 0xff.
+ */
+int nand_check_erased_ecc_chunk(void *data, int datalen,
+				void *ecc, int ecclen,
+				void *extraoob, int extraooblen,
+				int bitflips_threshold)
+{
+	int data_bitflips = 0, ecc_bitflips = 0, extraoob_bitflips = 0;
+
+	data_bitflips = nand_check_erased_buf(data, datalen,
+					      bitflips_threshold);
+	if (data_bitflips < 0)
+		return data_bitflips;
+
+	bitflips_threshold -= data_bitflips;
+
+	ecc_bitflips = nand_check_erased_buf(ecc, ecclen, bitflips_threshold);
+	if (ecc_bitflips < 0)
+		return ecc_bitflips;
+
+	bitflips_threshold -= ecc_bitflips;
+
+	extraoob_bitflips = nand_check_erased_buf(extraoob, extraooblen,
+						  bitflips_threshold);
+	if (extraoob_bitflips < 0)
+		return extraoob_bitflips;
+
+	if (data_bitflips)
+		memset(data, 0xff, datalen);
+
+	if (ecc_bitflips)
+		memset(ecc, 0xff, ecclen);
+
+	if (extraoob_bitflips)
+		memset(extraoob, 0xff, extraooblen);
+
+	return data_bitflips + ecc_bitflips + extraoob_bitflips;
+}
+EXPORT_SYMBOL(nand_check_erased_ecc_chunk);
+
 /**
  * nand_read_page_raw - [INTERN] read raw page data without ecc
  * @mtd: mtd info structure
@@ -1103,6 +1217,16 @@
 
 		stat = chip->ecc.correct(mtd, p,
 			&chip->buffers->ecccode[i], &chip->buffers->ecccalc[i]);
+		if (stat == -EBADMSG &&
+		    (chip->ecc.options & NAND_ECC_GENERIC_ERASED_CHECK)) {
+			/* check for empty pages with bitflips */
+			stat = nand_check_erased_ecc_chunk(p, chip->ecc.size,
+						&chip->buffers->ecccode[i],
+						chip->ecc.bytes,
+						NULL, 0,
+						chip->ecc.strength);
+		}
+
 		if (stat < 0) {
 			mtd->ecc_stats.failed++;
 		} else {
@@ -1152,6 +1276,15 @@
 		int stat;
 
 		stat = chip->ecc.correct(mtd, p, &ecc_code[i], &ecc_calc[i]);
+		if (stat == -EBADMSG &&
+		    (chip->ecc.options & NAND_ECC_GENERIC_ERASED_CHECK)) {
+			/* check for empty pages with bitflips */
+			stat = nand_check_erased_ecc_chunk(p, eccsize,
+						&ecc_code[i], eccbytes,
+						NULL, 0,
+						chip->ecc.strength);
+		}
+
 		if (stat < 0) {
 			mtd->ecc_stats.failed++;
 		} else {
@@ -1204,6 +1337,15 @@
 		chip->ecc.calculate(mtd, p, &ecc_calc[i]);
 
 		stat = chip->ecc.correct(mtd, p, &ecc_code[i], NULL);
+		if (stat == -EBADMSG &&
+		    (chip->ecc.options & NAND_ECC_GENERIC_ERASED_CHECK)) {
+			/* check for empty pages with bitflips */
+			stat = nand_check_erased_ecc_chunk(p, eccsize,
+						&ecc_code[i], eccbytes,
+						NULL, 0,
+						chip->ecc.strength);
+		}
+
 		if (stat < 0) {
 			mtd->ecc_stats.failed++;
 		} else {
@@ -1231,6 +1373,7 @@
 	int i, eccsize = chip->ecc.size;
 	int eccbytes = chip->ecc.bytes;
 	int eccsteps = chip->ecc.steps;
+	int eccpadbytes = eccbytes + chip->ecc.prepad + chip->ecc.postpad;
 	uint8_t *p = buf;
 	uint8_t *oob = chip->oob_poi;
 	unsigned int max_bitflips = 0;
@@ -1250,19 +1393,29 @@
 		chip->read_buf(mtd, oob, eccbytes);
 		stat = chip->ecc.correct(mtd, p, oob, NULL);
 
-		if (stat < 0) {
-			mtd->ecc_stats.failed++;
-		} else {
-			mtd->ecc_stats.corrected += stat;
-			max_bitflips = max_t(unsigned int, max_bitflips, stat);
-		}
-
 		oob += eccbytes;
 
 		if (chip->ecc.postpad) {
 			chip->read_buf(mtd, oob, chip->ecc.postpad);
 			oob += chip->ecc.postpad;
 		}
+
+		if (stat == -EBADMSG &&
+		    (chip->ecc.options & NAND_ECC_GENERIC_ERASED_CHECK)) {
+			/* check for empty pages with bitflips */
+			stat = nand_check_erased_ecc_chunk(p, chip->ecc.size,
+							   oob - eccpadbytes,
+							   eccpadbytes,
+							   NULL, 0,
+							   chip->ecc.strength);
+		}
+
+		if (stat < 0) {
+			mtd->ecc_stats.failed++;
+		} else {
+			mtd->ecc_stats.corrected += stat;
+			max_bitflips = max_t(unsigned int, max_bitflips, stat);
+		}
 	}
 
 	/* Calculate remaining oob bytes */
@@ -1361,8 +1514,7 @@
 	int ret = 0;
 	uint32_t readlen = ops->len;
 	uint32_t oobreadlen = ops->ooblen;
-	uint32_t max_oobsize = ops->mode == MTD_OPS_AUTO_OOB ?
-		mtd->oobavail : mtd->oobsize;
+	uint32_t max_oobsize = mtd_oobavail(mtd, ops);
 
 	uint8_t *bufpoi, *oob, *buf;
 	int use_bufpoi;
@@ -1712,10 +1864,7 @@
 
 	stats = mtd->ecc_stats;
 
-	if (ops->mode == MTD_OPS_AUTO_OOB)
-		len = chip->ecc.layout->oobavail;
-	else
-		len = mtd->oobsize;
+	len = mtd_oobavail(mtd, ops);
 
 	if (unlikely(ops->ooboffs >= len)) {
 		pr_debug("%s: attempt to start read outside oob\n",
@@ -1845,8 +1994,7 @@
  * Not for syndrome calculating ECC controllers, which use a special oob layout.
  */
 static int nand_write_page_raw(struct mtd_info *mtd, struct nand_chip *chip,
-				const uint8_t *buf, int oob_required,
-				int page)
+			       const uint8_t *buf, int oob_required, int page)
 {
 	chip->write_buf(mtd, buf, mtd->writesize);
 	if (oob_required)
@@ -1861,6 +2009,7 @@
  * @chip: nand chip info structure
  * @buf: data buffer
  * @oob_required: must write chip->oob_poi to OOB
+ * @page: page number to write
  *
  * We need a special oob layout and handling even when ECC isn't checked.
  */
@@ -1907,8 +2056,8 @@
  * @page: page number to write
  */
 static int nand_write_page_swecc(struct mtd_info *mtd, struct nand_chip *chip,
-				  const uint8_t *buf, int oob_required,
-				  int page)
+				 const uint8_t *buf, int oob_required,
+				 int page)
 {
 	int i, eccsize = chip->ecc.size;
 	int eccbytes = chip->ecc.bytes;
@@ -2029,6 +2178,7 @@
  * @chip: nand chip info structure
  * @buf: data buffer
  * @oob_required: must write chip->oob_poi to OOB
+ * @page: page number to write
  *
  * The hw generator calculates the error syndrome automatically. Therefore we
  * need a special oob layout and handling.
@@ -2103,7 +2253,7 @@
 						  oob_required, page);
 	else if (subpage)
 		status = chip->ecc.write_subpage(mtd, chip, offset, data_len,
-						  buf, oob_required, page);
+						 buf, oob_required, page);
 	else
 		status = chip->ecc.write_page(mtd, chip, buf, oob_required,
 					      page);
@@ -2145,7 +2295,6 @@
  * @oob: oob data buffer
  * @len: oob data write length
  * @ops: oob ops structure
- * @page: page number to write
  */
 static uint8_t *nand_fill_oob(struct mtd_info *mtd, uint8_t *oob, size_t len,
 			      struct mtd_oob_ops *ops)
@@ -2214,8 +2363,7 @@
 	uint32_t writelen = ops->len;
 
 	uint32_t oobwritelen = ops->ooblen;
-	uint32_t oobmaxlen = ops->mode == MTD_OPS_AUTO_OOB ?
-				mtd->oobavail : mtd->oobsize;
+	uint32_t oobmaxlen = mtd_oobavail(mtd, ops);
 
 	uint8_t *oob = ops->oobbuf;
 	uint8_t *buf = ops->datbuf;
@@ -2404,10 +2552,7 @@
 	pr_debug("%s: to = 0x%08x, len = %i\n",
 			 __func__, (unsigned int)to, (int)ops->ooblen);
 
-	if (ops->mode == MTD_OPS_AUTO_OOB)
-		len = chip->ecc.layout->oobavail;
-	else
-		len = mtd->oobsize;
+	len = mtd_oobavail(mtd, ops);
 
 	/* Do not allow write past end of page */
 	if ((ops->ooboffs + ops->ooblen) > len) {
@@ -2597,7 +2742,7 @@
 
 		/* Check if we have a bad block, we do not erase bad blocks! */
 		if (!instr->scrub && nand_block_checkbad(mtd, ((loff_t) page) <<
-					chip->page_shift, 0, allowbbt)) {
+					chip->page_shift, allowbbt)) {
 			pr_warn("%s: attempt to erase a bad block at page 0x%08x\n",
 				    __func__, page);
 			instr->state = MTD_ERASE_FAILED;
@@ -2684,7 +2829,20 @@
  */
 static int nand_block_isbad(struct mtd_info *mtd, loff_t offs)
 {
-	return nand_block_checkbad(mtd, offs, 1, 0);
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	int chipnr = (int)(offs >> chip->chip_shift);
+	int ret;
+
+	/* Select the NAND device */
+	nand_get_device(mtd, FL_READING);
+	chip->select_chip(mtd, chipnr);
+
+	ret = nand_block_checkbad(mtd, offs, 0);
+
+	chip->select_chip(mtd, -1);
+	nand_release_device(mtd);
+
+	return ret;
 }
 
 /**
@@ -2756,9 +2914,6 @@
 		return -EINVAL;
 #endif
 
-	/* clear the sub feature parameters */
-	memset(subfeature_param, 0, ONFI_SUBFEATURE_PARAM_LEN);
-
 	chip->cmdfunc(mtd, NAND_CMD_GET_FEATURES, addr, -1);
 	for (i = 0; i < ONFI_SUBFEATURE_PARAM_LEN; ++i)
 		*subfeature_param++ = chip->read_byte(mtd);
@@ -3491,7 +3646,7 @@
 			if (find_full_id_nand(mtd, chip, type, id_data, &busw))
 				goto ident_done;
 		} else if (*dev_id == type->dev_id) {
-				break;
+			break;
 		}
 	}
 
@@ -3514,10 +3669,7 @@
 
 	chip->chipsize = (uint64_t)type->chipsize << 20;
 
-	if (!type->pagesize && chip->init_size) {
-		/* Set the pagesize, oobsize, erasesize by the driver */
-		busw = chip->init_size(mtd, chip, id_data);
-	} else if (!type->pagesize) {
+	if (!type->pagesize) {
 		/* Decode parameters from extended ID */
 		nand_decode_ext_id(mtd, chip, id_data, &busw);
 	} else {
@@ -3621,7 +3773,6 @@
  * This is the first phase of the normal nand_scan() function. It reads the
  * flash ID and sets up MTD fields accordingly.
  *
- * The mtd->owner field must be set to the module of the caller.
  */
 int nand_scan_ident(struct mtd_info *mtd, int maxchips,
 		    struct nand_flash_dev *table)
@@ -3797,7 +3948,7 @@
 			ecc->write_oob = nand_write_oob_std;
 		if (!ecc->read_subpage)
 			ecc->read_subpage = nand_read_subpage;
-		if (!ecc->write_subpage)
+		if (!ecc->write_subpage && ecc->hwctl && ecc->calculate)
 			ecc->write_subpage = nand_write_subpage_hwecc;
 
 	case NAND_ECC_HW_SYNDROME:
@@ -3875,10 +4026,8 @@
 		}
 
 		/* See nand_bch_init() for details. */
-		ecc->bytes = DIV_ROUND_UP(
-				ecc->strength * fls(8 * ecc->size), 8);
-		ecc->priv = nand_bch_init(mtd, ecc->size, ecc->bytes,
-					       &ecc->layout);
+		ecc->bytes = 0;
+		ecc->priv = nand_bch_init(mtd);
 		if (!ecc->priv) {
 			pr_warn("BCH ECC initialization failed!\n");
 			BUG();
@@ -3913,11 +4062,11 @@
 	 * The number of bytes available for a client to place data into
 	 * the out of band area.
 	 */
-	ecc->layout->oobavail = 0;
-	for (i = 0; ecc->layout->oobfree[i].length
-			&& i < ARRAY_SIZE(ecc->layout->oobfree); i++)
-		ecc->layout->oobavail += ecc->layout->oobfree[i].length;
-	mtd->oobavail = ecc->layout->oobavail;
+	mtd->oobavail = 0;
+	if (ecc->layout) {
+		for (i = 0; ecc->layout->oobfree[i].length; i++)
+			mtd->oobavail += ecc->layout->oobfree[i].length;
+	}
 
 	/* ECC sanity check: warn if it's too weak */
 	if (!nand_ecc_strength_good(mtd))
@@ -4002,18 +4151,6 @@
 }
 EXPORT_SYMBOL(nand_scan_tail);
 
-/*
- * is_module_text_address() isn't exported, and it's mostly a pointless
- * test if this is a module _anyway_ -- they'd have to try _really_ hard
- * to call us from in-kernel code if the core NAND support is modular.
- */
-#ifdef MODULE
-#define caller_is_module() (1)
-#else
-#define caller_is_module() \
-	is_module_text_address((unsigned long)__builtin_return_address(0))
-#endif
-
 /**
  * nand_scan - [NAND Interface] Scan for the NAND device
  * @mtd: MTD device structure
@@ -4021,19 +4158,12 @@
  *
  * This fills out all the uninitialized function pointers with the defaults.
  * The flash ID is read and the mtd/chip structures are filled with the
- * appropriate values. The mtd->owner field must be set to the module of the
- * caller.
+ * appropriate values.
  */
 int nand_scan(struct mtd_info *mtd, int maxchips)
 {
 	int ret;
 
-	/* Many callers got this wrong, so check for it for a while... */
-	if (!mtd->owner && caller_is_module()) {
-		pr_crit("%s called with NULL mtd->owner!\n", __func__);
-		BUG();
-	}
-
 	ret = nand_scan_ident(mtd, maxchips, NULL);
 	if (!ret)
 		ret = nand_scan_tail(mtd);
@@ -4041,9 +4171,6 @@
 }
 EXPORT_SYMBOL(nand_scan);
 
-module_init(nand_base_init);
-module_exit(nand_base_exit);
-
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Steven J. Hill <sjhill@realitydiluted.com>");
 MODULE_AUTHOR("Thomas Gleixner <tglx@linutronix.de>");
diff --git a/drivers/mtd/nand/nand_bbt.c b/drivers/mtd/nand/nand_bbt.c
index 152f3bc..74c4c9a 100644
--- a/drivers/mtd/nand/nand_bbt.c
+++ b/drivers/mtd/nand/nand_bbt.c
@@ -1,6 +1,4 @@
 /*
- *  drivers/mtd/nand_bbt.c
- *
  *  Overview:
  *   Bad block table support for the NAND driver
  *
@@ -65,7 +63,6 @@
 #include <linux/mtd/mtd.h>
 #include <linux/mtd/bbm.h>
 #include <linux/mtd/nand.h>
-#include <linux/mtd/nand_ecc.h>
 #include <linux/bitops.h>
 #include <linux/string.h>
 
@@ -718,7 +715,7 @@
 		/* Must we save the block contents? */
 		if (td->options & NAND_BBT_SAVECONTENT) {
 			/* Make it block aligned */
-			to &= ~((loff_t)((1 << this->bbt_erase_shift) - 1));
+			to &= ~(((loff_t)1 << this->bbt_erase_shift) - 1);
 			len = 1 << this->bbt_erase_shift;
 			res = mtd_read(mtd, to, len, &retlen, buf);
 			if (res < 0) {
@@ -1073,15 +1070,15 @@
  * The bad block table memory is allocated here. It must be freed by calling
  * the nand_free_bbt function.
  */
-int nand_scan_bbt(struct mtd_info *mtd, struct nand_bbt_descr *bd)
+static int nand_scan_bbt(struct mtd_info *mtd, struct nand_bbt_descr *bd)
 {
 	struct nand_chip *this = mtd_to_nand(mtd);
-	int len, res = 0;
+	int len, res;
 	uint8_t *buf;
 	struct nand_bbt_descr *td = this->bbt_td;
 	struct nand_bbt_descr *md = this->bbt_md;
 
-	len = mtd->size >> (this->bbt_erase_shift + 2);
+	len = (mtd->size >> (this->bbt_erase_shift + 2)) ? : 1;
 	/*
 	 * Allocate memory (2bit per block) and clear the memory bad block
 	 * table.
@@ -1097,10 +1094,9 @@
 	if (!td) {
 		if ((res = nand_memory_bbt(mtd, bd))) {
 			pr_err("nand_bbt: can't scan flash and build the RAM-based BBT\n");
-			kfree(this->bbt);
-			this->bbt = NULL;
+			goto err;
 		}
-		return res;
+		return 0;
 	}
 	verify_bbt_descr(mtd, td);
 	verify_bbt_descr(mtd, md);
@@ -1110,9 +1106,8 @@
 	len += (len >> this->page_shift) * mtd->oobsize;
 	buf = vmalloc(len);
 	if (!buf) {
-		kfree(this->bbt);
-		this->bbt = NULL;
-		return -ENOMEM;
+		res = -ENOMEM;
+		goto err;
 	}
 
 	/* Is the bbt at a given page? */
@@ -1124,6 +1119,8 @@
 	}
 
 	res = check_create(mtd, buf, bd);
+	if (res)
+		goto err;
 
 	/* Prevent the bbt regions from erasing / writing */
 	mark_bbt_region(mtd, td);
@@ -1131,6 +1128,11 @@
 		mark_bbt_region(mtd, md);
 
 	vfree(buf);
+	return 0;
+
+err:
+	kfree(this->bbt);
+	this->bbt = NULL;
 	return res;
 }
 
@@ -1369,5 +1371,3 @@
 
 	return ret;
 }
-
-EXPORT_SYMBOL(nand_scan_bbt);
diff --git a/drivers/mtd/nand/nand_bch.c b/drivers/mtd/nand/nand_bch.c
index d7f6ce0..c145203 100644
--- a/drivers/mtd/nand/nand_bch.c
+++ b/drivers/mtd/nand/nand_bch.c
@@ -86,7 +86,7 @@
 		}
 	} else if (count < 0) {
 		printk(KERN_ERR "ecc unrecoverable error\n");
-		count = -1;
+		count = -EBADMSG;
 	}
 	return count;
 }
@@ -94,9 +94,6 @@
 /**
  * nand_bch_init - [NAND Interface] Initialize NAND BCH error correction
  * @mtd:	MTD block structure
- * @eccsize:	ecc block size in bytes
- * @eccbytes:	ecc length in bytes
- * @ecclayout:	output default layout
  *
  * Returns:
  *  a pointer to a new NAND BCH control structure, or NULL upon failure
@@ -110,14 +107,21 @@
  * @eccsize = 512  (thus, m=13 is the smallest integer such that 2^m-1 > 512*8)
  * @eccbytes = 7   (7 bytes are required to store m*t = 13*4 = 52 bits)
  */
-struct nand_bch_control *
-nand_bch_init(struct mtd_info *mtd, unsigned int eccsize, unsigned int eccbytes,
-	      struct nand_ecclayout **ecclayout)
+struct nand_bch_control *nand_bch_init(struct mtd_info *mtd)
 {
+	struct nand_chip *nand = mtd_to_nand(mtd);
 	unsigned int m, t, eccsteps, i;
-	struct nand_ecclayout *layout;
+	struct nand_ecclayout *layout = nand->ecc.layout;
 	struct nand_bch_control *nbc = NULL;
 	unsigned char *erased_page;
+	unsigned int eccsize = nand->ecc.size;
+	unsigned int eccbytes = nand->ecc.bytes;
+	unsigned int eccstrength = nand->ecc.strength;
+
+	if (!eccbytes && eccstrength) {
+		eccbytes = DIV_ROUND_UP(eccstrength * fls(8 * eccsize), 8);
+		nand->ecc.bytes = eccbytes;
+	}
 
 	if (!eccsize || !eccbytes) {
 		printk(KERN_WARNING "ecc parameters not supplied\n");
@@ -145,7 +149,7 @@
 	eccsteps = mtd->writesize/eccsize;
 
 	/* if no ecc placement scheme was provided, build one */
-	if (!*ecclayout) {
+	if (!layout) {
 
 		/* handle large page devices only */
 		if (mtd->oobsize < 64) {
@@ -171,7 +175,7 @@
 		layout->oobfree[0].offset = 2;
 		layout->oobfree[0].length = mtd->oobsize-2-layout->eccbytes;
 
-		*ecclayout = layout;
+		nand->ecc.layout = layout;
 	}
 
 	/* sanity checks */
@@ -179,7 +183,7 @@
 		printk(KERN_WARNING "eccsize %u is too large\n", eccsize);
 		goto fail;
 	}
-	if ((*ecclayout)->eccbytes != (eccsteps*eccbytes)) {
+	if (layout->eccbytes != (eccsteps*eccbytes)) {
 		printk(KERN_WARNING "invalid ecc layout\n");
 		goto fail;
 	}
@@ -203,6 +207,9 @@
 	for (i = 0; i < eccbytes; i++)
 		nbc->eccmask[i] ^= 0xff;
 
+	if (!eccstrength)
+		nand->ecc.strength = (eccbytes * 8) / fls(8 * eccsize);
+
 	return nbc;
 fail:
 	nand_bch_free(nbc);
diff --git a/drivers/mtd/nand/nand_ids.c b/drivers/mtd/nand/nand_ids.c
index fdd0074..561d2cd 100644
--- a/drivers/mtd/nand/nand_ids.c
+++ b/drivers/mtd/nand/nand_ids.c
@@ -1,6 +1,4 @@
 /*
- *  drivers/mtd/nandids.c
- *
  *  Copyright (C) 2002 Thomas Gleixner (tglx@linutronix.de)
  *
  * This program is free software; you can redistribute it and/or modify
@@ -41,6 +39,10 @@
 	 * listed by full ID. We list them first so that we can easily identify
 	 * the most specific match.
 	 */
+	{"TC58NVG0S3E 1G 3.3V 8-bit",
+		{ .id = {0x98, 0xd1, 0x90, 0x15, 0x76, 0x14, 0x01, 0x00} },
+		  SZ_2K, SZ_128, SZ_128K, 0, 8, 64, NAND_ECC_INFO(1, SZ_512),
+		  2 },
 	{"TC58NVG2S0F 4G 3.3V 8-bit",
 		{ .id = {0x98, 0xdc, 0x90, 0x26, 0x76, 0x15, 0x01, 0x08} },
 		  SZ_4K, SZ_512, SZ_256K, 0, 8, 224, NAND_ECC_INFO(4, SZ_512) },
@@ -58,8 +60,8 @@
 		  SZ_16K, SZ_8K, SZ_4M, 0, 6, 1280, NAND_ECC_INFO(40, SZ_1K) },
 	{"H27UCG8T2ATR-BC 64G 3.3V 8-bit",
 		{ .id = {0xad, 0xde, 0x94, 0xda, 0x74, 0xc4} },
-		  SZ_8K, SZ_8K, SZ_2M, 0, 6, 640, NAND_ECC_INFO(40, SZ_1K),
-		  4 },
+		  SZ_8K, SZ_8K, SZ_2M, NAND_NEED_SCRAMBLING, 6, 640,
+		  NAND_ECC_INFO(40, SZ_1K), 4 },
 
 	LEGACY_ID_NAND("NAND 4MiB 5V 8-bit",   0x6B, 4, SZ_8K, SP_OPTIONS),
 	LEGACY_ID_NAND("NAND 4MiB 3,3V 8-bit", 0xE3, 4, SZ_8K, SP_OPTIONS),
diff --git a/drivers/mtd/nand/ndfc.c b/drivers/mtd/nand/ndfc.c
index ee353c7..0a9849e 100644
--- a/drivers/mtd/nand/ndfc.c
+++ b/drivers/mtd/nand/ndfc.c
@@ -1,6 +1,6 @@
 /*
  * Overview:
- *   Platform independend driver for NDFC (NanD Flash Controller)
+ *   Platform independent driver for NDFC (NanD Flash Controller)
  *   integrated into IBM/AMCC PPC4xx cores
  *
  * (C) Copyright 2006-2009
diff --git a/drivers/mtd/nand/omap_gpmc.c b/drivers/mtd/nand/omap_gpmc.c
index cac9eea..37c4341 100644
--- a/drivers/mtd/nand/omap_gpmc.c
+++ b/drivers/mtd/nand/omap_gpmc.c
@@ -163,7 +163,7 @@
 				return 0;
 			printf("Error: Bad compare! failed\n");
 			/* detected 2 bit error */
-			return -1;
+			return -EBADMSG;
 		}
 	}
 	return 0;
diff --git a/drivers/mtd/nand/s3c2410_nand.c b/drivers/mtd/nand/s3c2410_nand.c
index 2a0da6e..dd742a6 100644
--- a/drivers/mtd/nand/s3c2410_nand.c
+++ b/drivers/mtd/nand/s3c2410_nand.c
@@ -104,7 +104,7 @@
 		return 0;
 
 	printf("s3c24x0_nand_correct_data: not implemented\n");
-	return -1;
+	return -EBADMSG;
 }
 #endif
 
diff --git a/drivers/mtd/nand/vf610_nfc.c b/drivers/mtd/nand/vf610_nfc.c
index dfbefc6..f99bdaf 100644
--- a/drivers/mtd/nand/vf610_nfc.c
+++ b/drivers/mtd/nand/vf610_nfc.c
@@ -146,7 +146,6 @@
 };
 
 struct vf610_nfc {
-	struct mtd_info *mtd;
 	struct nand_chip chip;
 	void __iomem *regs;
 	uint buf_offset;